Incompat with Cleanroom

[kappa-maintainer]

First, this obfuscated check is not needed in Cleanroom, it should be 26 in both dev and prod
Second, HashMap.computeIfAbsent() from here throws ConcurrentModificationException if called recursively in newer java, it should be changed to a manual null check
I could patch all of them by Mixin or ASM, but it's a bad idea to patch mods that still maintaining

[Xplodin]

oh thats why my textures bug out